Facing for insulation and other applications

ABSTRACT

A method and material for covering exposed insulation surfaces to protect them from moisture and other environmental factors. The covering typically includes a first, exposed layer of a metal-containing foil, a second layer of a metal-containing foil, a layer of a polymer disposed between the first two layers of foil, a third layer of a metal-containing foil, and a second layer of polymer disposed between the second and third layers of foil. A layer of a pressure sensitive adhesive is applied to one of the exposed layers of foil, and the pressure sensitive adhesive layer is covered with a release liner prior to application. The foil provides the necessary moisture and weather seal while the polymer provides the necessary strength and puncture resistance. The overall thickness of the laminate typically is less than 100 microns, permitting it to be easily cut and manipulated at the job site while providing an effective, long lasting weather seal.

FIELD OF THE INVENTION

[0001] This invention relates generally to insulation products for usewith fluid conduits, such as pipes or ducts, and more particularly, to afacing material for use with insulation surrounding fluid conduits forproviding a vapor barrier and a weather seal.

BACKGROUND OF THE INVENTION

[0002] Pipes or duct work in dwellings, commercial buildings andindustrial plants are used for heating or air conditioning purposes andtherefore carry fluids, such as heated or cooled air, or steam. Inindustrial applications, pipes or duct work also may carry chemicals orpetroleum products or the like. Such pipes or duct work and associatedheating or air conditioning units typically are covered with an exteriorlayer of insulation. The duct work typically is formed of aluminum orsteel, while the pipes may be formed of any suitable material, such ascopper, steel, aluminum, plastic, rubber or other like materials.

[0003] The insulation used to cover such pipes or duct work andassociated heating and air conditioning units often includes fiberglassor mineral wool, foamed cellular glass or a rigid foam, covered by ajacket of foil or a layer of paper, such as kraft paper. Other layers ofmaterials may be included in the insulation jacket, such as a layer offoil, a scrim, or a layer of polyester. Duct board is often used tocover duct work.

[0004] When such pipes or duct work are in a location exposed to weatheror when they are in other environments where the exterior insulationsurface is subject to degradation by moisture or the like, it is commonto cover the insulation with a facing. This is particularly true forinsulation having an exterior layer of paper or for duct board, (whetheror not the surface is a metalized layer or a paper layer) to protect theinsulation from moisture, sun, wind or other weather elements.

[0005] In one existing example, sheet metal cladding is applied to theexterior surface of the insulation. Such cladding typically is formed ofaluminum, stainless steel, galvanized steel, or another like metal. Thiscladding has certain drawbacks including the fact that such cladding isvery expensive and time consuming to install. In addition, metalcladding is not water or vapor tight or weatherproof because of joints,any repairs can be quite costly, prefabrication of the cladding isrequired off site, and metal cladding is very heavy and thereforedifficult to handle.

[0006] Another existing solution is to cover the insulation with butylrubber. However, this solution also has drawbacks including the factthat the butyl rubber does not perform well and tends to delaminate,particularly in extreme weather conditions. Butyl rubber also is verydifficult to apply because it is messy to cut and form, and it is veryheavy. Moreover, butyl rubber has been known to cause delamination ofthe outer surface of the insulation from the fiberglass or the wooldisposed in the interior because of its weight and because of its lackof strength at elevated temperatures. A butyl rubber covering tends tohave a poor appearance, and does not perform well at temperatures belowzero degrees Fahrenheit or above 120° Fahrenheit and therefore shouldnot be used in extreme weather environments where such exteriorcoverings are most desired and are often necessary. Butyl rubber alsotends to creep, has a poor fire and smoke rating, and therefore is notUL listed. Finally, solvents are required to activate butyl rubber attemperatures below 45° F.

[0007] It is also known to cover insulation with thin layers of aluminumfoil using a butyl rubber adhesive. However, such coverings have littleor no puncture resistance and the adhesive layer has the same drawbacksnoted above, including a tendency to run or ooze at elevatedtemperatures.

[0008] Scrim and mastics are also used to cover insulation. However, theuse of such materials often is very labor intensive and requires amultiple step process. These products can only be applied during certainweather conditions, and it is very difficult to regulate the thicknessof mastic to make it uniform. Consequently, such products have verylimited applications, and generate a poor appearance.

[0009] Another known product is bitumen felt and netting. This productis very labor intensive to apply and is not recommended for exterioruse. It also has a very poor fire rating, and is unsightly. Thus, itsuse is very limited.

[0010] In view of the foregoing, there exists a need for a material orfacing for covering insulation, particularly exterior insulation, thatis relatively inexpensive, easy to apply, provides a good appearance andprovides the desired vapor and weather seal. There also is a need for aproduct which is fire resistant, has low maintenance costs and can beused in extreme temperature conditions.

SUMMARY OF INVENTION

[0011] This invention relates generally to a facing material forapplication to exposed surfaces of insulation or other like materials toprovide a vapor seal and to protect the insulation from weather relateddamage. The facing of this invention overcomes the drawbacks of theprior art systems discussed above, since it is relatively inexpensive,is easy to apply, provides a good appearance, is easily cut andmanipulated at the job site and provides a 100% vapor seal. The facingof this invention also can be applied and will maintain its integrity inextreme weather conditions and is very fire resistant. This inventionalso relates to a method for applying a facing to insulation.

[0012] In one aspect, the invention includes a facing for insulation.One embodiment of the facing includes a first layer of ametal-containing foil, a second layer of a metal-containing foil, athird layer of a metal-containing foil, and a first layer of a punctureresistant polymer film disposed between the first and second layers offoil, and a second layer of a puncture resistant polymer film disposedbetween the second and third layers of foil. In another embodiment, alayer of pressure sensitive adhesive is applied to the third layer offoil. In yet another embodiment, at least the first layer ofmetal-containing foil may be formed of aluminum. In another embodiment,at least the first layer of the puncture resistant polymer film isformed of polyester. A typically thickness for the metal-containing foillayers is about 9 microns, while a typical thickness of the punctureresistant polymer film layers is about 23 microns or greater, althoughthe polymer film layers could be as thin as 5 microns.

[0013] In another aspect, a weather seal for use on exposed surfaces isdisclosed. This weather seal includes a first layer of an aluminum foil,a second layer of a metal-containing foil, a third layer of ametal-containing foil, a first layer of a puncture resistant materialdisposed between the first layer of aluminum foil and the second layerof metal-containing foil, a second layer of a puncture resistantmaterial disposed between the second and third layers ofmetal-containing foil and a layer of a pressure sensitive adhesivedisposed on the third layer of metal-containing foil. In one embodiment,the first and second layers of puncture resistant material are formed ofpolyester. In another embodiment, the combined thickness of the weatherseal is less than 100 microns. In another embodiment, the second andthird layers of metal-containing foil are formed of a metalized foil.

[0014] In another aspect, a covering for exterior and interiorinsulation is disclosed. This covering includes a first layer ofaluminum foil having a thickness in the range of from about 5 microns toabout 50 microns, a first layer of polyester adhered to the first layerof aluminum foil with an adhesive, the polyester layer having athickness greater than about 23 microns, a second layer of aluminum foiladhered to the first layer of polyester material by an adhesive, thesecond layer of aluminum foil having a thickness in the range of fromabout 5 microns to about 50 microns, a second layer of polyestermaterial adhered to the second layer of aluminum foil by an adhesive,the second layer of polyester material having a thickness greater thanabout 23 microns, a third layer of aluminum foil adhered to the secondlayer of polyester material by an adhesive, the third layer of aluminumfoil having a thickness in the range of from about 5 microns to about 50microns, and a pressure sensitive adhesive layer disposed on the thirdlayer of aluminum foil.

[0015] In yet another aspect of the invention, a covering for insulationis provided which includes multiple layers of a metal-containing foiland multiple layers of a puncture resistant, polymer film. The layers ofpuncture resistant polymer film are alternated with the layers of ametal-containing foil. The covering also includes a layer of a pressuresensitive adhesive disposed on one side of the covering, and on theother, exposed side of the covering, a layer of material resistant toultraviolet radiation, acid rain, and salt. The covering is sufficientlyflexible that it may be conformed to the shape of an insulated pipe.

[0016] In another aspect, a method for protecting insulation from damagedue to moisture and other environmental factors is disclosed. Thismethod includes the step of providing a covering material having ametal-containing layer on one surface and a layer of a pressuresensitive adhesive on a second surface, as well as a layer of a punctureresistant material disposed between the metal-containing layer and theadhesive layer, cutting the covering manually at a job site to form afirst sheet, removing the release liner covering the pressure sensitiveadhesive on the first sheet, applying the first sheet to the insulationso that the adhesive layer bonds to the insulation and themetal-containing layer is exposed, and applying additional sheets ofcovering material directly to the insulation such that each sheet ofcovering material overlaps sheets of covering material directly adjacentthereto.

[0017] In one embodiment, the method is used for covering an insulatedduct having a substantially rectangular cross-sectional shape. In thisembodiment, the applying steps include applying the first sheet ofcovering material to a bottom wall so that at least a three inch portionextends upwardly along each sidewall, applying a cut sheet of coveringmaterial to each side wall of the insulated duct so that it overlaps theportion of the sheet along the bottom wall which extends upwardly alongthe side wall, and so that a portion of the sheet material along eachside wall extends along the top wall, and applying a fourth sheet ofcovering material to the top wall to overlap the portions of the sheetsalong the side wall which extend along the top wall.

[0018] In another embodiment of the invention, where the pipe to beinsulated has a curved portion, lengths of a pressure sensitive adhesivetape having a metal-containing foil layer and a puncture resistantpolymer layer are wrapped about the sheets of covering material toconform the covering material to the configuration of the pipe.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The objects, advantages and features of this invention will bemore clearly appreciated from the following detailed description, whentaken in conjunction with the accompanying drawings, in which:

[0020]FIG. 1 is a cross-sectional view of a cutaway portion of oneembodiment of the facing of this invention;

[0021]FIG. 1A is a cross-sectional view of a cutaway portion of anotherembodiment of the facing of this invention;

[0022]FIG. 1B is a cross-sectional view of a cutaway portion of yetanother embodiment of the facing of this invention;

[0023]FIG. 2 is a cross sectional schematic view of rectangular ductwork illustrating a method for applying the facing of FIG. 1 to ductwork:

[0024]FIG. 3 is a perspective schematic view illustrating a method forapplying the facing of FIG. 1 to a cylindrical, straight pipe;

[0025]FIG. 4 is a perspective, schematic view illustrating a method forapplying the facing of FIG. 1 to a curved pipe;

[0026]FIG. 5 is a perspective, schematic view illustrating a method forapplying the facing of FIG. 1 to a reduced portion of rectangular ductwork;

[0027]FIG. 6 is a perspective, schematic view illustrating a method forapplying the facing of FIG. 1 to a reduced pipe;

[0028]FIG. 6A is a plan view of a precut facing segment to be applied toa tapered portion of a reduced pipe;

[0029]FIG. 7 is a perspective schematic view illustrating a method forapplying the facing of FIG. 1 to a T-section pipe; FIG. 7A is a planview of precut facing segments to be applied to a T-section pipe; and

[0030]FIG. 8 is a cross-sectional view of a cutaway portion of awrapping tape to be used in the method of this invention.

DETAILED DESCRIPTION

[0031] With reference now to the drawings, and more particularly to FIG.1 thereof, one embodiment of the facing structure of this invention willbe described. Facing 10 includes multiple layers of a metal or metalizedfoil and a puncture-resistant polymer film which are laminated together.The layers of foil provide the desired vapor seal, weather resistance,and a desirable exterior appearance. The layers of polymer providepuncture and tear resistance, particularly with respect to birds andother animals. All of the materials together provide the desired fireresistance and resistance to flame spread.

[0032] The number of layers of foil and polymer, the thickness of eachlayer, and the actual materials forming the layers are chosen to providea facing which optimizes each of the desired properties. For example,thick layers of metal would provide additional resistance to weathering,impermeability to moisture, resistance to puncture, and additionalstrength. However, if the metal layers become too thick, they cannot beeasily cut and manually applied at the job site. The material also couldbecome too heavy to be easily manipulated, conformed and applied by theaverage worker. Similarly, additional layers of a polymer film, orgreater thicknesses of polymer film would increase the punctureresistance of the facing but could also increase the weight, reduce theconformability and render cutting more difficult, thus making it verydifficult to apply at the job site and to conform it to the shape of thefluid conduits about which it is to be wrapped. Any failure to conformthe facing closely to the shape of the insulation surrounding theconduit could produce gaps through which moisture or wind could enter,thus destroying the weather and vapor seal and permitting the damage tothe insulation it is designed to prevent. Different materials alsoprovide different advantages. For example, steel provides greaterstrength and puncture resistance, while aluminum is lighter in weight,cheaper, more easily cut and more flexible. A metalized foil is lighterin weight than most metal foils, but generally is not as strong or asimpermeable to moisture. Polytetrafluoroethylene (PTFE) is water proof,but is hard to cut and expensive. Polyester is cheaper and easier to cutand use than PTFE.

[0033] The embodiment illustrated in FIG. 1 represents a considerationof all of these factors and a balancing of the desired properties toachieve an optimal result. This embodiment includes a first layer 12 ofa metal-containing foil, a layer 14 of a polymer film, another layer 16of a metal-containing foil, another layer 18 of a polymer film, and athird layer 20 of a metal-containing foil. A pressure sensitive adhesivelayer 22 is disposed adjacent foil layer 20. Prior to application,pressure sensitive adhesive layer 22 is covered by a release liner 24.

[0034] Layers 12, 16 and 20 typically are formed either of a metalizedfoil or of a metal foil. In one embodiment, layers 12, 16 and 20 areformed of an aluminum foil. It is understood however, that other metalfoils could be used for layers 12, 16 and 20, such as a stainless steelfoil, a titanium foil, a copper foil, or the like. In anotherembodiment, foil layers 12, 16 and 20 are formed of a metalized foil.Metalized foils suitable for use in this invention include conventional,commercially available foils in which a metal, such as aluminum, steelor titanium, is vapor deposited on a substrate formed of a polymer, suchas polyvinyl fluoride (sold under the name TEDLAR®), polyethylene orbiaxially oriented polypropylene. Since metalized foils tend to have pinholes resulting from handling during manufacture or other causes, it ispreferred that not all of layers 12, 16 and 20 be formed of a metalizedfoil. Preferably, at least one of layers 12, 16 and 20 is formed of ametal foil, such as aluminum. In a preferred embodiment, at least layer12 is formed of a metal foil, although it is understood that layer 12could be formed of a metalized foil, so long as one of layers 16 and 20is formed of a metal foil. If only one of layers 12, 16 and 20 is formedof a metal foil, it is preferred that such a layer have a thickness ofat least nine microns to provide the desired impermeability to moisture.If more than one of layers 12, 16 and 20 is formed of a metal foil, itis preferred that the total thickness of metal foil layers in facing 10be at least nine microns, and more preferably 25 microns.

[0035] Layers 14 and 18 typically are formed of a polyester filmalthough other polymer films such as polypropylene, polyethylene,polyurethane, Nylon®, Dacron®, Kevlar®, or polytetrafluoroethylene couldbe used.

[0036] Layers 12, 14, 16, 18 and 20 preferably are laminated or bondedtogether such as by an adhesive. This laminating adhesive could be apressure sensitive adhesive or any conventional, flame retardantadhesive which is suitable for laminating a metal foil to a polymer, andwhich has high strength and durability. In one embodiment, aconventional urethane laminating adhesive is used, such as that, soldunder the name Boscadur and purchased from the Bostik Chemical Divisionof the Emhart Fastener Group in Middleton, Mass. 01949. Another adhesiveis sold under the name Adcote by Rohm & Haas. Typically, theselaminating adhesives are provided in layers of about 0.3 to 2.0 mils andcoating weights of about 3 to 11 pounds per 1000 square feet.

[0037] Layer 22 of a pressure sensitive adhesive can be any commerciallyavailable, pressure sensitive adhesive that is suitable for bonding to ametal or metalized foil and to kraft paper or other insulation surfaces,and which maintains its integrity under low and high temperatureconditions. Examples of such suitable pressure sensitive adhesives aredisclosed in U.S. Pat. No. 4,780,347, which is specifically incorporatedherein by reference. In particular, one suitable adhesive is a pressuresensitive, acrylic adhesive, which when cured, approaches a 100% acryliccompound in which substantially all solvents have been removed. Thisadhesive can, however, tolerate up to 1% solvents after curing and stillperform as desired. When cured, layer 22 formed of this particularacrylic adhesive typically has a thickness of between about 1.0 and 5mils and a coating weight of about 5.5 to about 27.5 pounds per 1000square feet. This particular acrylic adhesive is especially desirable,since it remains tacky and useable at temperatures as low as minus 17°Fahrenheit and as high as 284° Fahrenheit.

[0038] Release liner 24 can be any conventional release liner suitablefor use with an acrylic adhesive. A typical release liner is a siliconecoated, natural kraft paper release liner rated at 70 pounds per ream.

[0039] In one embodiment, where foil layers 12, 16 and 20 are formed ofa metal foil, each layer 12, 16 and 20 is about 9 microns in thickness.However, especially for aluminum foils, thicknesses as low as 5 micronsalso would be suitable for many applications, while thickness as greatas 50 microns would be acceptable, since facing 10 would still becuttable with a knife or scissors and would still be sufficientlyconformable to be used in covering most types of installations in mostapplications.

[0040] In one embodiment, layers 14 and 18 may be about 23 microns orgreater in thickness. However, it is to be understood that layers 14 and18 could be thinner than 23 microns, depending upon the degree ofpuncture and tear resistance desired. In fact, layers 14 and 18 could beas thin as 5 microns for certain applications. In addition, these layers14 and 18 may also be as thick as 50 microns so long as the resultingfacing 10 is still adequately conformable to the shape of the fluidconduit and the insulation surrounding it, and the facing 10 could stillbe cut with scissors or a knife. Preferably, the total thickness offacing 10 is 100 microns or less to allow it to be easily cut andhandled at the job site. If the facing could be precut at the factoryprior to transportation to the job site, much thicker layers of polymerand foil could be utilized to provide enhanced performance as long asthe material still conformed to the outer shape of theinsulation-covered conduit.

[0041] In one embodiment in which layers 12, 16 and 20 are formed of analuminum foil having a thickness of about 9 microns, and in which layers14 and 18 are formed of a polyester film having a thickness of about 23microns, the total thickness of facing 10, not including adhesive layer22, is about 85 microns. This thickness includes the thicknesses of thelaminating adhesives used to bond together the layers. In thisembodiment, a typically thickness of adhesive layer 22 is about 0.079millimeters with a coating weight of about 50 grams per square meter.The peel adhesion is about 30 ounces per inch and the sheer adhesion isindefinite at 2.2 pounds per square inch. The tensile strength measuredaccording to PSTC-31 is about 50 pounds per inch width. The elongationat break is at about 166%. The puncture resistance according to ASTMD-1000 is about 16 kilograms, while the tear strength according to ASTMD-624 is about 2 kilograms. A maximum temperature for continuous use isabout 300° Fahrenheit (149° C.), and the application temperature rangesfrom minus 17° Fahrenheit to 284° Fahrenheit (minus 27° C. to plus 140°C.). Facing 10 has no permeability to water vapor. Facing 10 has achemical and ultraviolet resistance which is comparable to that ofaluminum.

[0042]FIGS. 1A and 1B illustrate other embodiment of the facing 10 ofthis invention. Like numbers are used for like parts, where appropriate.In FIG. 1A, a protective layer 26 is disposed on top of layer 12 offacing 10. Protective layer 26 protects layer 12, and thus all of thelayers below layer 12 from damage caused by the environment. Preferably,protective layer 26 protects against damage due to ultravioletradiation, and/or acid rain, and/or salt and/or other corrosivematerials found in the environment. In one embodiment, protective layer26 is a cured epoxy coating which is deposited on layer 12 while wet andallowed to cure. Other materials which could be used for layer 26include a urethane material, polyvinyl fluoride, an acrylic material, ametalized film of polyvinyl fluoride, a metalized titanium film, a layerof silica vapor deposited upon layer 12 or layer of Saran®.

[0043] In another embodiment, as illustrated in FIG. 1B, facing 10 couldbe provided without adhesive layer 22 or release liner 24. In theabsence of adhesive layer 22, a user could apply facing 10 directly toinsulation at the factory prior to shipment to a job site. In such aninstance, the facing 10 could be applied utilizing a conventional hotmelt adhesive, or any other standard adhesive. If facing 10 of FIG. 1Bis sent directly to the job site, the user could apply facing 10 to theinsulation utilizing a mastic, or conventional adhesive, which is eitherapplied to layer 20, or which is applied to the insulation prior toapplication of the facing 10.

[0044] Another alternative embodiment of the structure of FIG. 1 isillustrated in FIG. 1A in which an additional layer 15 is incorporatedinto the structure of FIG. 1 between a layer 12 of a metal-containingfoil and a layer 14 of polymer film. This additional layer 15 can beincorporated between any two layers in the structure, but typically isnot disposed on an outside surface, or adjacent adhesive layer 22. Thislayer could be formed of a fiberglass scrim, a polyester scrim, a wovenfabric or a fiberglass and a polyester scrim. The woven fabric could beformed of a polypropylene or a polyester thread. Such a layer 15provides additional tensile strength, and tear resistance. In addition,a scrim layer produces a pattern on the exterior surface of facing 10that is rectangular in shape, and that aids the installer in properlyaligning the facing 10 on the insulation.

[0045] Moreover, additional layers of a metal-containing foil and apolymer could be added to the structure of FIG. 1 so long as theresulting product were sufficiently conformable, easy to cut andlightweight. Additional layers could be accommodated by making thinnerthe alternating metal-containing layers and polymer layers. In addition,it is to be understood that layer 22 of a pressure sensitive adhesivecould be applied to polymer layer 18 rather than to a metal-containinglayer, as illustrated in FIG. 1.

[0046] Methods of use of facing 10 in various applications will now bedescribed with reference to FIGS. 2-7. Before applying the facing 10 toany surface, it is important that the surface be dry, clean and freefrom dust, oil and grease or silicone. Facing 10 should be cut to sizeprior to application. Typically, cutting to size is performed at thejobsite so that the worker can measure the fluid conduit or duct work onthe spot and cut the facing to the precise size desired. However, facing10 could be precut at the factory, particularly for the portions used oncurved pipes, as shown in FIG. 4, or on T-sections, as shown in FIG. 7.Typically, facing 10 comes in large rolls which are unrolled and thencut with scissors, knives, box cutters or the like. It is important thatthe sheets of facing 10 be applied in an overlapping fashion, to providea weather and vapor proof seal. A three inch (75 millimeter) overlap isrecommended. When applying sheets of the facing 10, typically releaseliner 24 is peeled back from one edge and creased to expose adhesivelayer 22 along that edge. This edge is then adhered to the surface towhich the facing is to be applied, and thereafter, release liner 24 ispeeled away from adhesive layer 22 as the facing is applied, such as byuse of a spreader which smoothes the facing and the insulation surface.

[0047] One method for applying a sheet of facing 10 to rectangular ductwork 30 is illustrated in FIG. 2. Typically, a sheet 32 of facing 10 isfirst applied to the bottom wall 31 of the duct 30 and the necessaryoverlap 34 is provided along walls 33 and 35. Typically, one edge ofsheet 32 is first adhered to wall 33 or 35 to provide overlap 34, whilethe remainder of the sheet 32 remains covered by release liner 24. Assheet 32 is secured to wall 31, release liner 24 is peeled away fromadhesive layer 22 just prior to adhering sheet 32 to wall 31. Theprocess continues until all of wall 31 is covered, and the necessaryoverlap 34 is provided along the other of wall 33 or 35. Thereafter,another sheet 36 or 38 of facing is applied along respective wall 33 or35. In both instances, the overlap 34 typically is provided along wall37. Once walls 33 and 35 have been covered, top wall 37 is covered inthe manner previously described with sheet 40. Sheet 40 need not overlapwalls 33 and 35. Typically, no additional sealing tape is required forsuch rectangular duct work 30, or the like. This process is repeatedalong the entire axial or longitudinal length of the duct work 30 withadditional sheets of facing 10 that overlap adjacent sheets in alongitudinal direction along circumferentially extending edges. Thistechnique is particularly advantageous for large, flat horizontalductwork upon the top wall 37 of which water tends to pool. By using asheet on the top wall 37 that extends the width of the wall and overlapswalls 33 and 35, there are no seams into which the pooled water mayseep.

[0048] An example of a method of application of this facing 10 to astraight circular pipe 48 is illustrated in FIG. 3. In this example, aseries of sheets 52 having the same width and length are cut from rollsof the facing 10 prior to installation. Each sheet 52 is sized so thatwhen wrapped about the insulation 46 on pipe 48, a suitablecircumferential overlap 50 results along axially extending edges.Similarly, when successive sheets 52 are applied, there should be anoverlap 54 between each successive sheet 52 in an axial direction alongcircumferentially extending adjacent edges. Each sheet 52 is otherwiseapplied in the same manner as described with respect to FIG. 2.

[0049]FIG. 4 illustrates one example of application of facing to acurved pipe 64. Initially, sheets 60 are applied in a manner virtuallyidentical to sheets 52 of FIG. 3. Successive sheets 60 are cut andapplied in an overlapping manner to insulation 62 along the axial lengthof pipe 64. One difference between the method of FIG. 3 and that of FIG.4 is that the sheet 60 applied to the curved portion 66 of pipe 64typically would be narrower in width in an axial direction than sheets60 covering the straight portion of the pipe 64, since facing 10 may notconform as easily to the shape of the curved portion 66 of the pipe 64as it does to the straight portions because of a slight inherentrigidity caused by the multiple layers of foil and polymer.

[0050] To assist in conforming sheet 60 to the shape of the curvedportion 66 of the pipe 64, in some applications, it may be desirable toapply a wrapping of a tape 68 at axially spaced intervals, as shown.Tape 68 typically is wrapped so as to overlap itself circumferentiallyand should be applied at whatever axial intervals are necessary toconform sheet 60 to the shape of curved portion 66. A tape 68 typicallyused for this purpose is a tape which has the same vapor barrier,weathering characteristics, and appearance as facing 10. In one example,as shown in FIG. 8, tape 68 is formed of a film 28 of a polymer disposedbetween two layers 27 and 29 of a metal-containing foil. The layers arelaminated together using a laminating adhesive, like that used forfacing 10. Like layers 12, 16 and 20 of facing 10, layers 27 and 29could be formed of a metalized foil or a metal such as aluminum, whilethe polymer film 28 can be formed of the same materials as layers 14 and18 of facing 10, such as polyester. Layers 27 and 29 and polymer film 28could be of the same construction and thickness as respective layers 12and 14 found in facing 10. Typically, a pressure sensitive adhesivelayer 25, similar to adhesive layer 22, is disposed on layer 29, and arelease liner 23, such as release liner 24 is applied to the layer 25 ofpressure sensitive adhesive.

[0051]FIG. 5 illustrates one example of the application of facing 10 toa reduced section of duct work 69. A first trapezoidal segment of facingis cut and applied to surface 70. This trapezoidal segment shouldprovide the desired overlap on each adjoining surface, includingsurfaces 74, 76, 78 and 80. Next, trapezoidal segments of facing are cutfor surfaces 74 and 80, providing the necessary overlap along adjoiningsurfaces 70, 86, 88 and 82. Thereafter, a final trapezoidal segment offacing is cut and applied to surface 82 with overlap provided alongsurfaces 90, 84, 80 and 74. Next, sheets are cut having the necessarycircumferential length to be wrapped about surfaces 76, 88 and 90 withthe necessary axial overlap along circumferential edges as well as withthe necessary overlap with each of the trapezoidal segments on surfaces70, 80, 82 and 74 and adjacent sheets in an axial direction alongcircumferentially extending edges. Finally, sheets of facing are cut tobe wrapped about surfaces 78, 84 and 86 to provide the necessary overlapwith the trapezoidal segments on surfaces 80, 82, 74 and 70, withadjoining sheets in an axial direction along surfaces 84, 86 and 78, andwith themselves in an axial direction along circumferentially extendingedges. Each sheet is applied as previously described.

[0052]FIG. 6 illustrates one example of the application of facing 10 toa reduced pipe 99. Typically, a sheet of facing is first applied tosurface 100 which is the reduced portion 101 of the pipe 99 justadjacent the tapered portion 102. A sheet of facing is cut and wrappedabout surface 100 in the manner previously described. Thereafter, aC-shaped section 105 of facing (see FIG. 6A) is cut and applied to thetapered portion 102, providing overlap with the material on surface 100.Sheets of facing 10 then are cut and applied to surface 104 of theenlarged portion 103 of the pipe 99. These sheets are applied oneadjacent another along the length of surface 104 so as to provideoverlap with each other in an axial direction and to provide overlapwith themselves as shown in a circumferential direction. Finally, sheetsof facing are applied to surface 106 in overlapping relationship withone another along the axial length, and with themselves in acircumferential direction, as previously described.

[0053]FIGS. 7 and 7a illustrate one example of the application of facing10 to a T section of a pipe 116. A first sheet 110 is cut having theconfiguration shown in FIG. 7a. Sheet 110 is provided with cutouts 112to accommodate the T section 114 of pipe 116. Thereafter, a sheet 120 iscut to the shape shown in FIG. 7a. Sheet 120 is then applied to section114 in the manner shown, so that there is overlap between edge 122 ofsheet 120 and edge 124 on sheet 110. Thereafter, additional overlappingsheets may be applied to segment 114, as well as to portion 126, aspreviously described with respect to a straight pipe in FIG. 3.Preferably a length of tape 128, like tape 68, is applied at thejunction of edges 122 and 124 to effect a vapor tight seal.

[0054] The facing 10 of this invention, when used with insulation for afluid conduit, such as a pipe or duct work, provides a vapor tight sealabout the insulation and duct work or pipe that is weather resistant,puncture and tear resistant, sufficiently flexible, easily cut, andaesthetically pleasing. Facing 10 can be applied in almost all weatherconditions, and in a temperature range from minus 17° to plus 284°Fahrenheit. The resulting sealed pipe or duct work is fire resistant,and any flame would spread very slowly. Facing 10 can be easily repairedonsite, and has a long life.

[0055] The method of this invention provides an easy technique forapplying facing to insulation disposed on duct work or on pipes and canbe mastered with very little training or skill. Installation is fast,clean and safe. Only scissors and a knife or the like are required astools, and all work can be done at the job site. No prior or cutting orassembly is required.

[0056] Modifications and improvements will occur within the scope ofthis invention to those skilled in the art. The above description isintended as exemplary only, the scope of this invention being defined bythe following claims and their equivalents.

What is claimed is:
 1. A covering for insulation comprising: a first layer of a metal-containing foil; a second layer of a metal-containing foil; a third layer of a metal-containing foil; a first layer of a puncture resistant polymer film disposed between said first and said second layers of metal-containing foil; and a second layer of a puncture resistant polymer film disposed between said second and said third layers of metal-containing foil.
 2. The covering as recited in claim 1 wherein at least said first layer of metal-containing foil is a sheet of aluminum foil.
 3. The covering as recited in claim 2 wherein said first foil layer has a thickness in the range of from about 5 microns to about 50 microns.
 4. The covering as recited in claim 3 wherein said first foil layer has a thickness of about 9 microns.
 5. The covering as recited in claim 1 wherein at least said first layer of a puncture resistant polymer film is formed of polyester.
 6. The covering as recited in claim 5 wherein said first layer of a puncture resistant polymer film has a thickness in the range of about 10 microns to about 50 microns.
 7. The covering as recited in claim 6 wherein said first layer of a puncture resistant polymer film material has a thickness of about 23 microns.
 8. The covering as recited in claim 1 wherein said first and said second layers of a metal-containing foil are bonded to the first layer of a puncture resistant polymer film by an adhesive, and wherein said second and said third layers of a metal-containing foil are bonded to said second layer of a puncture resistant polymer film by an adhesive.
 9. The covering as recited in claim 1 further comprising: a layer of a pressure sensitive adhesive applied to said third layer of a metal-containing foil; and a release liner covering said layer of a pressure sensitive adhesive.
 10. A weather seal for use on exposed surfaces comprising: a first layer of an aluminum foil; a second layer of a metal-containing foil; a third layer of a metal-containing foil; a first layer of a puncture resistant material disposed between said first layer of aluminum foil and said second layer of a metal-containing foil; a second layer of a puncture resistant material disposed between said second layer of a metal-containing foil and said third layer of a metal-containing foil; and a layer of a pressure sensitive adhesive disposed on said third layer of a metal-containing foil.
 11. The weather seal as recited in claim 10 wherein said first and said second layers of a puncture resistant material are formed of a polyester.
 12. The weather seal as recited in claim 10 wherein a combined thickness of said first layer of an aluminum foil, said second layer of a metal-containing foil, said third layer of a metal-containing foil, and said first and said second layers of a puncture resistant material is less than 100 microns.
 13. The weather seal is recited in claim 10 wherein said first layer of an aluminum foil has a thickness of about 9 microns.
 14. The weather seal is recited in claim 10 wherein said first and said second layers of a puncture resistant material each have a thickness of about 23 microns.
 15. The weather seal as recited in claim 10 wherein said second and said third layers of a metal-containing foil are formed of a metalized foil.
 16. A covering for exterior and interior insulation which may be applied to the insulation after installation comprising: a first layer of aluminum foil having a thickness in the range of from about 5 microns to about 50 microns; a first layer of polyester material adhered to said first layer of aluminum foil with an adhesive, said polyester layer having a thickness greater than about 23 microns; a second layer of aluminum foil adhered to said first layer of polyester material by an adhesive, said second layer of aluminum foil having a thickness in the range of from about 5 microns to about 50 microns; a second layer of polyester material adhered to said second layer of aluminum foil by an adhesive, said second layer of polyester material having a thickness greater than about 23 microns; a third layer of aluminum foil adhered to said second layer of polyester material by an adhesive, said third layer of aluminum foil having a thickness in the range of from about 5 to about 20 microns; and a pressure sensitive adhesive layer disposed on said third layer of aluminum foil which remains tacky in a temperature range of from about minus 17° Fahrenheit to about 284° Fahrenheit.
 17. A method for protecting insulation from damage due to moisture and other environmental factors, said method comprising: providing a covering material having a metal-containing layer on one surface and a layer of a pressure sensitive adhesive on a second, opposite surface, said covering material including at least one layer of a puncture resistant material disposed between the metal-containing layer and the adhesive layer; manually cutting from the covering material an appropriately sized first sheet at a job site; removing a release liner covering the pressure sensitive adhesive layer of the first sheet; applying the first sheet to the insulation so that the adhesive layer bonds to the insulation and the metal-containing layer is exposed; and applying additional sheets of covering material directly to the insulation such that each sheet of covering material overlaps sheets of covering material directly adjacent thereto.
 18. The method as recited in claim 17 wherein said manually cutting step comprises cutting the covering material into sheets having shapes that conform to an external shape and size of the insulation being covered.
 19. The method as recited in claim 17 further comprising, for a pipe having a curved portion, wrapping lengths of a pressure sensitive adhesive tape having a layer of a metal-containing foil and a layer of a puncture resistant polymer about the sheets of covering material to conform the covering material to the configuration of the pipe.
 20. The method as recited in claim 17 further comprising sealing seams between adjacent sheets of covering material with a pressure sensitive adhesive tape.
 21. The method as recited in claim 17 wherein the covering material is formed of a laminate of aluminum foil, and polyester in multiple, alternating layers.
 22. The method as recited in claim 17 wherein for an insulated duct having a substantially rectangular cross-sectional shape, the first and second applying steps comprise: applying the first sheet of covering material to a bottom wall of the duct so that an overlapping portion of the sheet extends upwardly along each side wall of the insulated duct immediately adjoining the bottom wall; thereafter applying a cut sheet of covering material to each side wall of the insulated duct so that each sheet on the side wall overlaps the overlapping portion of the first sheet extending upwardly from the bottom wall and so that another overlapping portion of each sidewall sheet of material extends beyond the side wall and along the top wall of the insulated duct; and applying a fourth sheet of a covering material to the top wall of the duct to overlap the overlapping portions of the sheets of material on the side wall which extend along the top wall.
 23. The covering as recited in claim 1 further comprising a protective layer disposed on said first layer of a metal-containing foil, said protective layer being resistant to ultraviolet radiation, acid and salt.
 24. The covering as recited in claim 1 wherein one of said first, second and third layers of a metal-containing foil is formed of a metal foil, and the others of said first, second and third layers of a metal-containing foil are formed of a metalized foil.
 25. A covering as recited in claim 1 where each of said first, second and third layers of a metal-containing foil is formed of a metal foil.
 26. A covering as recited in claim 1 further comprising a layer of scrim.
 27. A covering as recited in claim 1 further comprising additional, alternating layers of a metal-containing foil and a puncture resistant polymer film.
 28. A covering for insulation comprising: multiple layers of a metal-containing foil; multiple layers of a puncture resistant, polymer film, said layers of puncture resistant, polymer film alternating with said layers of a metal-containing foil; a layer of a pressure sensitive adhesive disposed on one side of said covering; and a layer of material disposed on a side of the covering that is opposite of the one side and that is exposed, the layer of material being resistant to ultraviolet radiation, acid rain and salt, said covering being sufficiently flexible that it may be conformed to the shape of an insulated pipe. 